The present invention relates to a system for plasma confinement by magnetic fields, and more particularly to a plasma confinement system having magnetic field generation equipment which is well suited for the highdensity plasma confinement of a nuclear fusion apparatus or the like.
The plasma confinement system produces a plasma within a toroidal vacuum chamber and exerts magnetic fields on the plasma so as to confine the plasma.
Conventional plasma confinement systems are based on pulse operations. With the intention of the A.C. operation of the system, there has been the idea that primary winding coils are excited by the use of alternating current as disclosed in Japanese Patent Application Laid-open No. 100891/1984. The operation on this occasion, however, has been quite equivalent to the ordinary pulse operation as regards the half cycle of the alternation.
In the Tokamak-type confinement system which is a typical conventional system, it is the ballooning instability that forms an obstacle to the future perfection of this system as a nuclear fusion reactor. This instability takes place for the reason that the outward convex part of a plasma swells outwards still more.
The system therefore has the problem that the plasma disappears in a short time and cannot be confined for a long time.